This finding concerns a vibratory finishing machine especially suited for uniformly depositing bitumen aggregate on surfaces to be asphalted. It is known that in road asphalting work common use is made of self-propelled machines called vibratory finishing machines which basically consist of a frame shaped to provide a driver""s cab and which houses the means of traction of the machine itself.
What""s more the frame also holds a hopper with mobile walls containing the hot bitumen aggregate that, when retrieved by a conveyor belt, is deposited on the surface being asphalted.
The bitumen aggregate is then uniformly spread onto the surface being asphalted by the action of a pair of screw feeders standing side by side and set crossways to the machine""s direction of travel and rotated by a transmission unit that connects them next to the machine""s centreline. While the bitumen aggregate is still hot it is uniformly spread over the road surface being asphalted and then compacted by the action of a device called a xe2x80x9cvibrating compactorxe2x80x9d set behind the screw feeders with respect to the machine""s direction of travel.
The vibratory compactor comprises a plowshare consisting of a plate having a primarily longitudinal direction, set perpendicular to the surface being asphalted and crossways to the machine""s direction of travel. In particular the plowshare spreads the bitumen aggregate distributed by the screw feeders thereby preparing it for compacting by a beam, which is also set crossways to the machine""s direction of travel and made to oscillate vertically by a device connected to it.
The main inconvenience of the machine described above is that the flow of bitumen aggregate transported by the conveyor belt engulfs the space between the screw feeders and the plowshare creating a build up of bitumen aggregate against the transmission unit which leads to an uneven distribution of the bitumen aggregate on the road course, thereby requiring additional finishing by hand.
This build up is also aggravated by the machine""s forward travel that pushes the bitumen aggregate against the plate. Another inconvenience is that the build up of bitumen aggregate tends to cool and thereby consolidates, hampering the uniform distribution of bitumen aggregate on the surface being asphalted. This makes it necessary to remove the consolidated bitumen aggregate, which has to be carried out periodically by an operator who has to follow the machine throughout the work cycle. Last but not least, an inconvenience is caused by the risk the operator runs while removing the consolidated bitumen aggregate, since he has to remove the bitumen aggregate with a spade in close proximity to the rotating screw feeders.
This finding intends to remedy the aforementioned inconveniences. The main scope of the finding is to produce a machine that allows to deposit the bitumen coarse in an even, uniform manner over the whole surface being treated.
Last but not least, a scope is to produce a machine that eliminates the build-up of hot bitumen aggregate and its consequent cooling. Another scope is to produce a machine that does not require the intervention of operators during the work cycle.
The aforesaid scopes are achieved by a self-propelled vibratory finishing machine for asphalting road surfaces that in accordance with the main claim comprises a frame, housing a means of traction, which is shaped to provide a driver""s cab and that supports:
storage means and distribution of the bitumen aggregate ready to be deposited on said surfaces comprising a pair of screw feeders working side by side mounted crossways to the direction of travel of said machine, moved by a transmission unit that connects them next to the machine""s centreline;
pressing means the deposited bitumen aggregate set behind said screw feeders and crossways to the direction of travel of said machine;
that is characterised in that it has, connected to said transmission unit and next to said screw feeders, a flow divider device basically consisting of faces symmetrically shaped around a vertical axis, converging towards said axis to create at least one cutting edge suited to aid the flow of bitumen aggregate towards said screw feeders.
An advantage of the finding is that it allows a uniform distribution of the bitumen aggregate deposited on the surface being asphalted. Another advantage of the finding is that it allows a vibratory finishing machine to be produced that does not require periodical servicing by operators to guarantee an even deposit of bitumen aggregate.